Jessica, who was diagnosed with leukemia in August, must find a bone-marrow match soon or she will die, her doctors say.

''I can relate to the pain the Fitzgeralds are going through,'' said Lisa Macierowski, 24, her eyes filling with tears.

Her 3-month-old child recently died from sudden infant death syndrome. ''I know what it's like to bury a baby.''

Macierowski joined pizza parlor worker Michael Rose, accountant Peter Yacino and Barbara Tubbs, whose 22-year-old hemophiliac son died last September. They had one common goal - to give Jessica a fighting chance.

''I've begged people for blood for the last 25 years,'' sobbed Tubbs, of Pine Hills. ''This is the least I can do.''

A steady stream of people holding test tubes walked to a conference room where nurses waited to fill the tubes with blood.

Jessica's father, Larry Fitzgerald, stood by with his youngest daughter, 4-year-old Elissa, and thanked each volunteer.

''This is overwhelming,'' Fitzgerald said. ''For people to take time out for something like this - for someone they don't know.''

Charles E. Pruitt, donor recruitment manager for Life-Savers Foundation of America, said those who had their blood screened will automatically become part of the National Marrow Donor Registry.

The registry program set up by Congress in 1987 helps keep track of potential bone-marrow donors. Volunteers are solicited at blood banks and through Life-Savers, Pruitt said.

So far this year, 77,000 potential donors have been screened by the non-profit organization and another 50,000 through blood banks, Pruitt said. The goal is to have 250,000 potential donors on file.

Leukemia is a cancer of the blood. In some cases, transplanting healthy marrow into the patient can result in a cure or remission of the deadly disease. Nationally, about 24 people a day die from leukemia or cancer.

More than 9,000 people nationwide currently need a transplant, Pruitt said. Half of them won't live to see it happen.

''Right now the people in Orlando are showing everyone they can make the difference,'' Pruitt said. ''People like Jessica don't have to die.''

Jessica is expected to come home this Friday. She is now undergoing chemotherapy at Shands Hospital in Gainesville. Doctors expect to have results from the blood screenings in about a week. If a match is made, she will go back to Shands for the bone-marrow transplant.

Winter Park Memorial Hospital has collected more than $17,000 toward the $45,000 it will cost to pay for Jessica Fitzgerald's search for a bone-marrow donor. Contributions can be made on behalf of Jessica Fitzgerald to Barnett Bank of Central Florida, P.O. Box 1000 (B0101), Winter Park, 32790.